Apparatus for treating waste water

ABSTRACT

Water treating apparatus is disclosed that has a first chamber to receive the waste water, a second chamber having a discharge provided with an overflow inlet and an expansion chamber extending downwardly into it to receive within it part of the second chamber contents, and means to transfer first chamber contents into the second chamber. Aeration may be effected in both chambers and when the transfer means into the second chamber and the second chamber aerating means are not working, the second chamber functions as a settling chamber. Means are provided then to deliver air into the expansion chamber to force water out of it thus to raise the second chamber level to cause an overflow through the discharge, the overflow being relatively clear after a predetermined settling interval.

United States Patent [191 Rust APPARATUS FOR TREATING WASTE WATERInventor: Kai Lennart Rost, Hallowell, Maine Pollutrol Industries Inc.,Portland, Maine Filed: July 22, 1971 App]. No.: 164,996

Related US. Application Data Assignee:

vContinuation of Ser. No. 57,290, July 22, 1970,

abandoned, which is a continuation of Ser. No. 794,118, Jan. 22, 1969,abandoned.

References Cited UNITED STATES PATENTS 9/1909 Greth ..2l0/124 X Foster..2l0/104 Primary Examiner-John Adee Attorney-Frank A. Steinhilper etal.

[5 7 ABSTRACT Water treating apparatus is disclosed that has a firstchamber to receive the waste water, a second chamber having a dischargeprovided with an overflow inlet and an expansion chamber extendingdownwardly into it to receive within it part of the second chambercontents, and means to transfer first chamber contents into the secondchamber. Aeration may be effected in both chambers and when the transfermeans into the second chamber and the second chamber aerating means arenot working, the second chamber functions as a settling chamber. Meansare provided then to deliver air into the expansion chamber to forcewater out of it thus to raise the second chamber level to cause anoverflow through the discharge, the overflow being relatively clearafter a predetermined settling interval.

24 Claims, 4 Drawing Figures PATHHEUHARZOISTS SHEET 10F 2Una00o000looomooooooanfloouooooww L M/VE/VTOR KAI LENNART ROST B) oscn &STEINHILPER SHEH 2 SF 2 00000000. oooynnhnonolnoboooooooocl BY RQSEN &STEINHILRER ATTORNEYS APPARATUS FOR TREATING WASTE WATER The presentinvention relates to apparatus for treating waste water and acontinuation of my co-pending application Ser. No. 57,290 filed July 22,1970 now abandoned which in turn is a continuation of my copendingapplication Ser. No. 794,118, filed Jan. 27, 1969, now abandoned.

While the disposal of waster water has always been a problem, pollutioncontrols impose requirements that are' not met by presently availablesystems because of their cost, because of their physical dimensions andbecause of the demand for increased efficiency.

The general objective of the present invention is to provide waste watertreatment apparatus that will meet the above generally indicatedrequirements, an objective attained by providing apparatus that consistsof a first chamber to receive the waste water, a second chamber having adischarge, and means to transfer first chamber contents into the secondchamber. Both chambers have aerating means. The second chamber has anexpansion chamber opening therein to receive part of its contents andprovided with air delivery an venting means.

With such apparatus, the second chamber becomes a settling chamber whenthe transfer and its aerating means are not in operation. With the airdelivery and venting means operated after a predetermined settlinginterval to deliver air into the expansion chamber, the pressure thereinbuilds up to force the liquid contents downwardly to increase the waterlevel in the second chamber externally of the expansion chamber with therelatively clear surface water flowing into the discharge.

Another objective of the invention is to provide a basis of controladapted to automatic operation. This objective is attained by providingmeans responsive to the water level in the second chamber to prevent theoperation of the transfer means unless there is a demand for water inthe second chamber as determined by its water leveland by providing forthe termination of the use of the secondchamber as a treating chamber byshutting off the air supply to the second chamber aerator when the waterlevel in the first chamber reaches a predetermined high water level.After a predetermined interval, the timed delivery of air into theexpansion chamber is commenced. At the end of timed interval, the waterlevel in the second chamber drops substantially because, the expansionchamber now being vented, water rises therein and aeration in the secondchamber is resumed. Because of the drop in the water level in the secondchamber, the transfer means are now operated until the low level in thefirst chamber is reached.

Another objective of the invention is to provide the second chamber witha series of pivoted slat members above the aerating means together withmeans to position them with the slat member vertically disposed exceptduring the interval in which the expansion chamber is connected to theair delivering means, the slat members then providing a floor. A furtherobjective of the invention is to have the operation of the slatscontrolled by timing means.

In the accompanying drawings, there is shown an embodiment of theinvention illustrative of these and other of its objectives, novelfeatures, and advantages.

In the drawings:

FlG. l is a top plan view of a water treatment plant in accordance withthe invention;

FIGS. 2 and 3 are sections taken along the indicated lines 2--2 and 33,respectively, of FIG. I; and

FIG. 4 is a schematic view of the air circulating and electrical systemsand one basis of control.

The treatment plant shown in the drawings consists of a tank having atransverse partition 11 dividing it into a first compartment 12 and asecond compartment 13.

A waste water conduit 14 discharges into the compartment 12 which thereis located an aerator 15 below a shield 16 to which air is delivered byan air conduit 17 from an air source such as a blower 18 driven by themotor 19 in a circuit 20 controlled by a timer 21 in a circuit 22 bywhich at predetermined intervals air is delivered to the aerator for apredetermined time.

A conduit 23 in the compartment 12 has it intake disposed adjacent thebottom thereof with its discharge openening through the partition 11 andinto the upper part of the compartment 13 at one side of a lengthwisepartition 24 extending part way towards the bottom thereof. An airconduit 25 discharges into the conduit 23 to establish, when thenormally closed valve 26 is opened by its solenoid 27, see FIG. 4, anair operated lift for transferring the contents of the compartment 12into the compartment 13. The various valves, solenoids and other controlcomponents are schematically shown in FIG. 4 and as they areconventional, they are not detailed. The conduit 25 is connected to aconduit 28 efiecting communication between the conduit 17 and an aerator29 extending lengthwise of the chamber 13 near the bottom thereof. Theconduit 28 has a normally opened valve 30 serving both the air liftconduit 25 and the aerator 29 and closed when its solenoid 31 isenergized.

The space on the side of the partition 24 that is opposite to that intowhich the discharge end of the air lift conduit 23 opens is closed by anair tight cover 32 provided with an air inlet 33 connected to an airconduit 34 having a vent 35 under the control of a normally open valve36 closed when its solenoid 37 is energized. The conduit 34 has anadjustable control valve 38 and is connected to the conduit 28 betweenthe valve 30 and the conduit 17. The space below the cover 32 and abovethe bottom edge of the partition 24 will hereafter be referred to as theexpansion compartment and it is generally indicated at 39.

At the side of the compartment 13 opposite the expansion compartment 39,there is a scum baffle 40 extending lengthwise of the compartment 13 andspaced from a weir channel 41 also extending lengthwise of thecompartment 13 and leading to the discharge 42 for treated water, seeFIG. 1.

A series of slat members 43 are pivotally supported in the compartment13 between the aerator 29 and the lower edge of the partition 24. Theslat members 43 are provided with cranks 44 joined together by aconnecting rod 45 and actuated against the influence of a return spring46 by an air operated piston 47 within a cylinder 48 to which air isdelivered by a conduit 49 provided with a normally closed, cylinderventing valve 50 opened when its solenoid 51 is energized. In the normalsituation, the slat members 43 are vertical but are disposedhorizontally to establish a floor when air is delivered into theexpansion chamber 29 with its vent 35 closed.

The operation of the apparatus will be detailed in connection withparticular reference to the control circuitry shown in FIG. 4.

A float 52 is confined in the chamber 12 by a suitable guide indicatedat 53 and has a stem 54 provided with adjustable stops 55 and 56 incontrol of the arm 57 of a switch 58 in a lead 59 from the circuit 22.The switch 58 is closed in response to the float 52 when the contents ofthe compartment 1 1 are at the high water mark and open when the waterlevel falls.

A float 60 is confined in the chamber 13 as by the vertical guide 61 andits stem 62 operated a switch 63 to connect the lead 59 to a lead 64when the liquid in the chamber 13 is at the indicated high water leveland to connect a lead 65 to the solenoid 27 when the liquid level in thechamber 13 drops to a predetermined extent.

The operating cycle may be most readily explained by assuming that thecompartment 12 is not full to its high water level and its contents areaerated at the intervals and for the intervals controlled by the timer21. As the valve 30 is in its normal open position, the compartment 13is being aerated and the vent 35 is open. The slat members 43 aredisposed vertically. When the high water level is reached in thecompartment 12, the switch 58 is closed in response to the upward travelof the float 52. If at this time, the compartment 13 was not full, theswitch 63 would be in a position connecting the lead 65 to the lead 59thereby energizing the solenoid 27 to open the valve 26 to place the airlift in operation until the rising water level caused the float 60 toactuate the switch 63 then to disconnect the lead 65 and connect thelead 64 to the lead 59.

The lead 64 has a branch lead 66 including the solenoid 31 which, whenenergized, closes the valve 30 thereby terminating the aeration of thecontents of the compartment 13. The lead 64 includes a first timer 67and the appropriate lead of the motor circuit thereby to provide an airsupply independently of the timer 21. The timer 67 at the end of apredetermined settling period closes a lead 68 to a second timer 69which closes for a predetermined period the lead 70 to the solenoid 37by which the valve 36 is closed whereby pressure begins a slot build upin the expansion compartment 39 forcing the liquid within it downwardlywith a corresponding increasing level of the liquid in the other side ofthe partition 24 until the relatively clear water overflows into theweir channel 41 and then to the discharge 42. A relief conduit 71 opensthrough the partition 24 adjacent its bottom edge and discharges abovethe high water level thus to prevent the escape of air under thepartition that would cause turbulence in the compartment 13. The secondtimer 69 also closes a lead 72 to the solenoid 51 which, when energized,results in the positioning of the slat members 43 as a floor overlyingsettled solids.

At the end of the timed interval, the leads 70 and 72 are both open withthe result that the slat members 43 return to their open or verticalpositions and the valve 36 opens permitting air to escape from theexpansion compartment 39 through the vent 35. As this occurs, the waterin the compartment 13 within and without the compartment 39 reaches thesame level and the drop in the level in the vicinity of the float causesit to drop with the switch 63 closing the lead thereby to energize thesolenoid 27 by which the valve 26 is opened to set the air operated liftin operation to transfer the contents of the compartment 12 to thecompartment 13 until the level in the latter so lifts the float 60 as toreset the switch 63 to mark the end of an operating cycle.

It will be appreciated that the high water level in the compartment 12at which the switch 58 is operated does not represent the maximumcapacity of the compartment 12 as space is provided for any waste waterthat can be expected during the timed interval in which aeration isstopped in the compartment 13 and after appropriate settling, the clearwater discharged to make room for the transfer of some of thecompartment 12 contents.

Iclaim:

1. A water treatment plant comprising a first chamber for the receptionof waste water, a second chamber including a discharge having an inletabove a predetermined high water level therein and an expansion chamberopening into the second chamber below said level to receive part of thesecond chamber liquid within it, aerating means for each chamber, meansin communication with both chambers and operable to transfer firstchamber contents into the second chamber, means to vent air from theexpansion chamber, and control means for the expansion chamber todeliver air into said expansion chamber and operable to force liquiddownwardly therefrom thereby to raise the water level in the secondchamber externally of the expansion chamber to overflow said dischargeinlet and to vent the expansion chamber from the second chamber to lowerthe water level therein whereby with the transfer means and the aeratingmeans for the second chamber inoperative the second chamber functions asa settling chamber and with the air delivery means to the expansionchamber operating and the vent means inoperative the displacement of theexpansion chamber contents causes the overflow of the relatively clearwater into the discharge.

2. The water treatment plant of claim 1 and means in control of theoperation of the transfer means to initiate its-operation when apredetermined high water level exists in the first chamber and apredetermined low water level exists in the second chamber and toterminate its operation when the high level is attained in the secondchamber.

3. The water treatment plant of claim 2 and a control for the secondchamber aerator operated by the means in control of the transfer meanswhen the high level in the second chamber is attained.

4. The water treatment plant of claim 2 in which the second chamberaerator includes a normally open, solenoid operated valve and a circuitto the solenoid includes switch means operated by the means in controlof the transfer means.

5. The water treatment plant of claim 4 in which the switch means isalso responsive to the water level in the first chamber.

6. The water treatment plant of claim 2 in which the transfer means is aconduit, an air delivery conduit is in communication with the interiorthereof to force liquid through and includes a normally closed, solenoidand switch means responsive to a low water level in the second chamber.

7. The water treatment plant of claim 1 in which the means to deliverair to the expansion chamber also includes a vent and a normally open,solenoid operated valve in control of said vent whereby the expansionchamber is normally vented, timing means, and a circuit controlled bythe timing means includes the solenoid of the vent-controlling valve.

8. The water treatment plant of claim 1 in which the control means forthe expansion chamber are operable in the alternative to deliver airinto the expansion chamber and to vent air therefrom.

9. The water treatment plant of claim 7 and timing means in control ofthe expansion chamber control means.

10. The water treatment plant of claim 8 in which the air delivery meansincludes a valve adjustable to control the flow of air to the expansionchamber.

11. The water treatment plant of claim 1 in which the second chamber hasa series of pivoted, parallel slat members above the second chamberaerating means, and operating means operable to turn the slat membersbetween vertical and horizontal positions, in their horizontal position,the slat members providing a floor.

12. The water treatment plant of claim 5 in which the second chamber hasa series of pivoted, parallel slat members above the second chamberaerating means, means operable to turn the slat members between verticaland horizontal positions, said member turning means including a controlmember having a first position in which the slat members are verticaland a solenoid operable to move the control member into a secondposition in which the horizontal positions of the slat members iseffected, a circuit controlled by the switch means including saidsolenoid and is closed with respect thereto when predetermined highwater levels exist in both chambers.

13. The water treatment plant of claim 1 and a contuit extending from apoint near the bottom of the expansion chamber above the high waterlevel in the second chamber to prevent turbulence that would disturbsettled solids.

14. The water treatment plant of claim 1 in which the second chamber hasan open discharge extending lengthwise thereof above the high waterlevel therein into which water overflows as water is expelled from theexpansion chamber.

15. The water treatment plant of claim 1 in which a scum barrier extendslengthwise of the second chamber close to the discharge.

16. The water treatment plant of claim 1 in which the second chamberincludes a lengthwise partition terminating above the bottom thereof butbelow the low water level therein and an air tight cover closes thespace between the partition and the side of the second chamber oppositethe transfer means.

17. The water treatment plant of claim 1 and a normally open valve incontrol of the second chamber aerating means and including avalve-closing solenoid, a normally closed valve in control of thetransfer means and including a valve-opening solenoid, the control meansfor the expansion chamber are normally operative to vent the expansionchamber and include solenoid means which when energized operate thecontrol means to deliver therein liquid expelling air, and a controlcircuit including switch means responsive to the water level in the twochambers and operable to energize the solenoid of the transfer meanswhen a high water level exists only in the first chamber, to energizethe solenoid means when a high water level exists in both chambers.

18. The water treatment plant of claim 17 in which the circuit includestiming means in control of the solenoid means.

19. The water treatment plant of claim 18 in which the timing meansprovide first a predetermined settling interval and then a predeterminedinterval in which air is delivered into the expansion chamber.

20. The water treatment plant of claim 19 in which there is a common airsource for the aerating means, the transfer means, and the air deliverymeans, the air source includes an electric motor and an operatingcircuit therefor including a timer whereby both chambers areperiodically subjected to aeration and the control circuit includes themotor when the solenoid means is energized.

21. The water treatment plant of claim 19 in which the second chamberhas a series of pivoted, parallel slat members above the second chamberaerating means, operating means to turn the slat members betweenvertical and horizontal positions, in their horizontal positions, theslat members providing a floor, means normally holding the slat membersin their vertical positions and including a solenoid to effect theirhorizontal positions when energized, and the circuit includes thatsolenoid during the interval air is delivered into the expansionchamber.

22. A water treatment plant comprising a first chamber for the receptionof waste water, a second chamber including a discharging means, a timedaerator in communication with the second chamber, means in communicationwith both chambers and operable to transfer first chamber contents intothe second chamber, means in control of the operation of the transfermeans to initiate its operation when a predetermined high water levelexists in the first chamber and a predetermined low water level existsin the second chamber and to terminate its operation when apredetermined high level is attained in the second chamber, and acontrol operated when the high level in the first chamber is attainedfirst to terminate aeration in the second chamber for a predeterminedinterval and then also to operate said discharging means for the balanceof that interval whereby said second chamber operates both as anaeration chamber and a settling chamber.

23. The treatment plant of claim 22 in which there is also an aerator incommunication with the first chamber and both aerators include a commonsource.

24. A water treatment plant comprising a first chamber for the receptionofwaste water, a second chamber including a discharging means, a timedaerator in communication with the second chamber, means in communicationwith both chambers and operable to transfer first chamber contents intothe second chamber, means in control of the operation of the transfermeans to initiate its operation when a predetermined high water levelexists in the first chamber and a predetermined low water level existsin the second chamber and to terminate its operation when apredetermined high level is attained in the second chamber and a controloperated first to aerate said second chamber then to terminate aerationin the second chamber for a predetermined interval, and then also tooperate said discharging means for the balance of that interval wherebysaid second chamber operates both as an aeration chamber and a settlingchamber.

1. A water treatment plant comprising a first chamber for the receptionof waste water, a second chamber including a discharge having an inletabove a predetermined high water level therein and an expansion chamberopening into the second chamber below said level to receive part of thesecond chamber liquid within it, aerating means for each chamber, meansin communication with both chambers and operable to transfer firstchamber contents into the second chamber, means to vent air from theexpansion chamber, and control means for the expansion chamber todeliver air into said expansion chamber and operable to force liquiddownwardly therefrom thereby to raise the water level in the secondchamber externally of the expansion chamber to overflow said dischargeinlet and to vent the expansion chamber from the second chamber to lowerthe water level therein whereby with the transfer means and the aeratingmeans for the second chamber inoperative the second chamber functions asa settling chamber and with the air delivery means to the expansionchamber operating and the vent means inoperative the displacement of theexpansion chamber contents causes the overflow of the relatively clearwater into the discharge.
 2. The water treatment plant of claim 1 andmeans in control of the operation of the transfer means to initiate itsoperation when a predetermined high water level exists in the firstchamber and a predetermined low water level exists in the second chamberand to terminate its operation when the high level is attained in thesecond chamber.
 3. The water treatment plant of claim 2 and a controlfor the second chamber aerator operated by the means in control of thetransfer means when the high level in the second chamber is attained. 4.The water treatment plant of claim 2 in which the second chamber aeratorincludes a normally open, solenoid operated valve and a circuit to thesolenoid includes switch means operated by the means in control of thetransfer means.
 5. The water treatment plant of claim 4 in which theswitch means is also responsive to the water level in the first chamber.6. The water treatment plant of claim 2 in which the transfer means is aconduit, an air delivery conduit is in communication with the interiorthereof to force liquid through and includes a normally closed, solenoidand switch means responsive to a low water level in the second chamber.7. The water treatment plant of claim 1 in which the means to deliverair to the expansion chamber also includes a vent and a normally open,solenoid operated valve in control of said vent whereby the expansionchamber is normally vented, timing means, and a circuit controlled bythe timing means includes the solenoid of the vent-controlling valve. 8.The water treatment plant of claim 1 in which the control means for theexpansion chamber are operable in the alternative to deliver air intothe expansion chamber and to vent air therefrom.
 9. The water treatmentplant of claim 7 and timing means in control of the expansion chambercontrol means.
 10. The water treatment plant of claim 8 in which the airdelivery means includes a valve adjustable to control the flow of air tothe expansion chamber.
 11. The water treatment plant of claim 1 in whichthe second chamber has a series of pivoted, parallel slat members abovethe second chamber aerating means, and operating means operable to turnthe slat members between vertical and horizontal positions, in theirhorizontal position, the slat members providing a floor.
 12. The watertreatment plant of claim 5 in which the second chamber has a series ofpivoted, parallel slat members above the second chamber aerating means,means operable to turn the slat meMbers between vertical and horizontalpositions, said member turning means including a control member having afirst position in which the slat members are vertical and a solenoidoperable to move the control member into a second position in which thehorizontal positions of the slat members is effected, a circuitcontrolled by the switch means including said solenoid and is closedwith respect thereto when predetermined high water levels exist in bothchambers.
 13. The water treatment plant of claim 1 and a contuitextending from a point near the bottom of the expansion chamber abovethe high water level in the second chamber to prevent turbulence thatwould disturb settled solids.
 14. The water treatment plant of claim 1in which the second chamber has an open discharge extending lengthwisethereof above the high water level therein into which water overflows aswater is expelled from the expansion chamber.
 15. The water treatmentplant of claim 1 in which a scum barrier extends lengthwise of thesecond chamber close to the discharge.
 16. The water treatment plant ofclaim 1 in which the second chamber includes a lengthwise partitionterminating above the bottom thereof but below the low water leveltherein and an air tight cover closes the space between the partitionand the side of the second chamber opposite the transfer means.
 17. Thewater treatment plant of claim 1 and a normally open valve in control ofthe second chamber aerating means and including a valve-closingsolenoid, a normally closed valve in control of the transfer means andincluding a valve-opening solenoid, the control means for the expansionchamber are normally operative to vent the expansion chamber and includesolenoid means which when energized operate the control means to delivertherein liquid expelling air, and a control circuit including switchmeans responsive to the water level in the two chambers and operable toenergize the solenoid of the transfer means when a high water levelexists only in the first chamber, to energize the solenoid means when ahigh water level exists in both chambers.
 18. The water treatment plantof claim 17 in which the circuit includes timing means in control of thesolenoid means.
 19. The water treatment plant of claim 18 in which thetiming means provide first a predetermined settling interval and then apredetermined interval in which air is delivered into the expansionchamber.
 20. The water treatment plant of claim 19 in which there is acommon air source for the aerating means, the transfer means, and theair delivery means, the air source includes an electric motor and anoperating circuit therefor including a timer whereby both chambers areperiodically subjected to aeration and the control circuit includes themotor when the solenoid means is energized.
 21. The water treatmentplant of claim 19 in which the second chamber has a series of pivoted,parallel slat members above the second chamber aerating means, operatingmeans to turn the slat members between vertical and horizontalpositions, in their horizontal positions, the slat members providing afloor, means normally holding the slat members in their verticalpositions and including a solenoid to effect their horizontal positionswhen energized, and the circuit includes that solenoid during theinterval air is delivered into the expansion chamber.
 22. A watertreatment plant comprising a first chamber for the reception of wastewater, a second chamber including a discharging means, a timed aeratorin communication with the second chamber, means in communication withboth chambers and operable to transfer first chamber contents into thesecond chamber, means in control of the operation of the transfer meansto initiate its operation when a predetermined high water level existsin the first chamber and a predetermined low water level exists in thesecond chamber and to terminate its operation when a predetermined highlevel is attained in the second chamber, and a control opErated when thehigh level in the first chamber is attained first to terminate aerationin the second chamber for a predetermined interval and then also tooperate said discharging means for the balance of that interval wherebysaid second chamber operates both as an aeration chamber and a settlingchamber.
 23. The treatment plant of claim 22 in which there is also anaerator in communication with the first chamber and both aeratorsinclude a common source.
 24. A water treatment plant comprising a firstchamber for the reception of waste water, a second chamber including adischarging means, a timed aerator in communication with the secondchamber, means in communication with both chambers and operable totransfer first chamber contents into the second chamber, means incontrol of the operation of the transfer means to initiate its operationwhen a predetermined high water level exists in the first chamber and apredetermined low water level exists in the second chamber and toterminate its operation when a predetermined high level is attained inthe second chamber and a control operated first to aerate said secondchamber then to terminate aeration in the second chamber for apredetermined interval, and then also to operate said discharging meansfor the balance of that interval whereby said second chamber operatesboth as an aeration chamber and a settling chamber.